1. Field of the Invention
The present invention relates to a wiper blade and a wiper system having the same.
2. Description of Related Art
A wiper system that wipes a windshield of a vehicle uses a wiper blade, which can effectively wipe the windshield even when the windshield is a curved glass. Specifically, one such wiper blade includes a lever assembly, which includes a plurality of levers rotatably connected to a blade rubber. The blade rubber and backing plates are held by the lever assembly to spread urging force, which is applied from a wiper arm connected to the lever assembly, to the entire length of the blade rubber. Such a wiper blade is called as a tournament wiper blade and is widely used.
Apart from the tournament wiper blade, another type of wiper blade has been proposed in, for example, Japanese Unexamined Patent Publication No. 2002-531325 corresponding to U.S. Pat. No. 6,523,218. Here, backing plates, which are received in backing grooves of a blade rubber and have a predetermined rigidity, are curved into a predetermined curved shape that corresponds to a curvature of the windshield. Urging force of a wiper arm connected to the wiper blade is spread to the entire length of the blade rubber through the backing plates without using the levers.
Due to the absence of the levers, a height of the wiper blade measured in a direction perpendicular to the windshield surface is reduced to achieve a lower profile of the wiper blade in comparison to the tournament wiper blade. Because of the lower profile, such a wiper blade shows high performance at the time of driving the vehicle at the relatively high speed and thereby restrains lifting of the wiper blade from the windshield and generation of wind noise. Furthermore, such a wiper blade normally includes a fin to further improve the performance at the time of driving the vehicle at the relatively high speed.
In the wiper blade disclosed in the above-described Japanese Unexamined Patent Publication No. 2002-531325, the backing plates are received in the grooves of the blade rubber, and cuts are made along the length of the blade rubber. Securing claws of retainers are received in the cuts of the blade rubber to hold the backing plates in the grooves. Thus, these retainers, which are exposed at an exterior of the wiper blade, deteriorate an appearance of the wiper blade. Furthermore, the blade rubber and the fin are integrally molded. Thus, when the blade rubber is worn, the blade rubber and/or the backing plates need to be replaced together with the fin. As a result, the integrated blade rubber and fin cause an increase in replacement costs of the blade rubber.
Apart from the above disclosed wiper blade, there has been also proposed a wiper blade, in which a blade rubber is bonded to one side of a single backing plate by adhesive, and a fin is bonded to the other side of the backing plate by adhesive. In this case, it is difficult for an ordinary user to bond the blade rubber to the curved backing plate in an appropriate manner at the time of replacing the blade rubber. Thus, the blade rubber replaced by the ordinary user often cannot achieve good performance.
Another type of wiper blade has been proposed in, for example, German Patent No. 2313939. A blade rubber, which wipes the windshield, is made of a rubber material. A backing plate, which spreads urging force to the entire length of the blade rubber is received in the blade rubber. After long term of use, the blade rubber is worn, and the backing plate changes its shape. Thus, a wiping performance of the wiper blade is deteriorated, and the blade rubber needs to be replaced together with the backing plate. In the above-described German patent No. 2313939, notches are formed in the backing plate, and distal ends of hooks of a holder connected to a wiper arm are bent relative to the notches to securely engage the hooks of the holder with the notches of the backing plate and thereby to restrain longitudinal movement of the backing plate and the holder. Thus, at the time of removing the holder from the backing plate, a dedicated tool is required to deform the hooks, and the removal of the holder from the backing plate using such a tool is difficult. Furthermore, when the backing plate and the holder are removed, the hooks of the holder may be deformed inappropriately and are difficult to reinstall. This results in difficulties in the replacement of the blade rubber of the wiper blade.